DESCRIPTION (Investigator's Abstract): This research project is aimed at the isolation and structural elucidation of novel antitumor agents from higher plants which have confirmed bioactivities. The prescreening bioassays are based on disease-oriented cytotoxicity against human tumor cell lines: A-549 (non-small cell lung cancer), HT-29 (colon cancer), and MCF-7 (breast cancer). Fractionation and purification of active constituents will be directed by selected bioassay. The structures of novel compounds will be elucidated by modern spectroscopic methods, including high field two-dimensional NMR, solid state NMR, mass spectrometry and X-ray crystallography. All active compounds will be submitted to the National Cancer Institute for further in vitro human tumor cell panels as well as in vivo xenograft evaluations. During the course of this investigation, continuing collection and prescreening of additional plants from Taiwan, North America, and India will be carried out to ensure reliable supplies of new active plants.